A group of storm chasers must deal with rivals and deadly tornadoes in order to conduct an experiment that could potentially save lives.
Bodger - Paul Douglas
In June 1969, Jo's Father watches the television as TV Meteorologist 1 talks about a potential tornado. Her Mother grabs Jo and they run to the storm cellar with Jo's Father. Jo calls for Toby, her dog and he runs after her. They run into the storm cellar, including Toby. Jo's Father runs to grab the cellar door as it starts to bang on its hinges. He is then sucked away by the tornado as it rips the door from its hinges.
In the present day, the GOES-8 weather satellite flies in space detecting weather patterns. At the National Severe Storms Laboratory or NSSL in Norman Oklahoma, NSSL Scientist - Murphy shows NSSL Scientist - Bryce data which shows their could possibly be a record number of tornadoes. Bill and Melissa are driving in their truck so Bill can get the divorce paperwork from Jo. Jo is on a van working on a Doppler satellite dish with the help of Beltzer. Meanwhile Dusty is in his school bus watching an Eric Clapton music video. Rabbit complains to Sanders about him folding the maps instead of rolling them up. Bill and Melissa arrive and Bill is greeted by his former team members, including Preacher, Joey, Haynes and Laurence and introduces Dusty to Melissa. Dusty, Preacher and Laurence mention Bill returning, but he insists he isn't. He asks Jo for the divorce papers and when she asks what the rush is, he tells her he is engaged to Melissa. Bill notices Jo didn't sign one of the pages and when she finds out Melissa is there, Jo goes to introduce herself. Jo then shows Bill the completed Dorothy unit, that he designed. Jo and Bill then explain to Melissa how Dorothy is supposed to work. Haynes then runs up and tells everyone a major storm is forming and Jo and her team pack up and drive away. Bill and Melissa then get into their truck and follow them when Bill remembers Jo didn't finish signing the paperwork.
Rabbit gives Jo the fastest route to get to the storm. As they are driving, Jonas and his team drive along side them. While trying to avoid one of Jonas' groups vehicles, Bill drives off the road and gets a flat tire. He parks at a mechanic shop and asks Diner Mechanic how long it will take to fix the tire. Jonas is recording a video about his machine called Digital Orthographic Telemeter or D.O.T. 3 in front of his team, Tony, Eric, a Mobile Lab Technician, Kubrick, Eddie, The Communicator, Bubba, Willie, Patty, Dean and Stanley. Bill notices the design is a copy of Dorothy and he runs over and knocks Jonas' hat off. Bill accuses Jonas of stealing his idea, but Jonas turns around and says Bill stole his idea. A fight breaks out and afterwards Bill tells Jo he will help her for one day to get Dorothy off the ground. Melissa goes into the diner to order a drink for her and Bill from a Waitress. Bill goes outside and stares at the sky and watches the way the wind blows. Melissa and Jo talk and Melissa mentions how accurately Bill can predict the weather. Melissa asks Jo if she still loves Bill and then accuses her of trying to keep Bill in her life. Melissa comes out with her and Bill's drink and he tells her they have to go and to follow him and Jo in their truck. Jonas notices Jo's team leaving and he tells his team to pack up and leave.
As they are driving Jo starts asking Bill questions about Melissa, but he tells her he doesn't want to fight. They then start to argue about their relationship. Jonas at first tells his team to head east, but when Eddie notices Jo's team headed west, Jonas has his team change direction and follow them. Bill and Jo drive towards a tornado on the ground and Bill drives into a rutted track in a field. The Tornado's path changes towards their direction and Bill crashes the truck into a bridge while trying to outrun the tornado. He and Jo hide under the bridge and the truck is lifted into the tornado. The truck then lands right in front of Melissa as she is driving. Jonas's team drives up and Eddie asks if they should stop, but Jonas tells him to keep on going. A new Dorothy is placed in the back of Bill's truck and he and Jo lead the team to find another tornado. Meanwhile, the NSSL scientists continue to monitor the storm. Bill is heading in the same direction as Jonas' team when he notices the angle of the tornado and tells Jo it is going to change direction. While driving towards a pair of tornadoes, a cow flies in front of Bill, Jo and Melissa. The truck is caught in between the two tornadoes and then dissipates and Bill has to comfort Melissa. When Jo's team stops, they convince her to take them all to her Aunt Meg's house.
They all drive to Aunt Meg's house and she warmly greets Bill and then the other team members and cooks them a meal of steak and eggs. TV Meteorologist 2 interviews Jonas about chasing tornadoes and Jonas brags about how he hopes to better predict tornadoes with his D.O.T. 3 machine. At dinner, Melissa asks why Bill is called "The Extreme" and Dusty tells her a story of when Bill was drunk and naked and offered a drink to a tornado then threw the bottle into the tornado and the bottle never hit the ground. Another storm develops and Jo's team leaves Meg's house and leave Wakita. Rabbit tells them a short cut and they exit a corn patch and almost hit Jonas and his team. Bill tells Jo to make a right turn and they turn off of the road while Jonas and his team continue on it. Bill and Jo continue on to deploy Dorothy while the rest of the team stay back. They stop the truck to deploy Dorothy, but can't release it in time and a light pole lands on the truck knocking off Dorothy and scattering the sensors. Jo tries to gather the sensors, but the tornado forms again near them. Bill realizes Jo still has issues from her Father's death and tells her nothing can bring her Father back and she still has him and Melissa hears it over the CB radio.
The NSSL Scientists notice three cells converging into one. Jo and her crew stop at the Galaxy Drive-In. Jo goes to the window and orders eight coffees from one of the Drive-In Girls. She then sits down and signs the divorce paperwork. Bill walks up and tells her he thinks the sensors are too light. Melissa is watching the news when TV Meteorologist 3 reports of another dangerous tornado in Canton, Oklahoma and the signal goes down. Dusty runs out of his bus and yells a tornado is coming their way. The tornado rips trough the drive-in as everyone takes cover. During the tornado, Preacher is hit in the head with a hub cap. The wind suddenly starts to pick up in Wakita and Aunt Meg gets up from reading her book. Dusty tells Jo the tornado has headed toward Wakita and everyone on the team packs up and leaves. Bill tells Melissa he is going to help Meg and she tells him she is going back home and leaving him. They arrive in Wakita and find it destroyed. Jo and Bill run into Meg's collapsing house. They hear Mose barking and find Meg trapped under some rubble. They pull her out and take her to a Paramedic who tells them they will keep Meg overnight. As Jo stares at Meg's lawn art, she has an idea how to make Dorothy fly into the tornado.
The team cut pieces of aluminum cans and place them inside of the data balls and Bill and Jo drive towards a massive tornado. They drop off another Dorothy in front of the tornado, but it is smashed by a large trunk debris and scatters everywhere. They are nearly crushed by a large fuel truck which is thrown from the tornado. Jonas and Eddie drive towards the tornado and tell their team to hold back. Bill warns Jonas to hold back in case the tornado shifts course, but he refuses to listen. A large piece of metal is thrown from the tornado and flies into Eddie and the truck is picked up by the tornado and thrown to the ground and explodes. As they are driving away, Bill and Jo have to drive through a house that falls in front of them. Jo preps the last Dorothy and they drive into a corn field and drive the truck in the path of the tornado and then jump out and run away as it heads in their direction. Dorothy successfully deploys and a stream of data is sent out. Jo and Bill run towards a farm and ultimately strap themselves to pipes in a shed. The giant tornado passes overhead and then dissipates. A family gets out of their storm cellar including a Farm Girl. Bill and Jo start talking about the future and then argue on who is going to do the data analysis versus running the lab and they kiss.